[ so? 1 
Although accounts had been received from various 
perfons of feveral hills fuppofed proper for the intended 
purpofe, fome better and fome worfe authenticated; yet, 
in order to be fure of finding the heft hill for the experi- 
ment, it v'as determined to fend a perfon furniflied with 
proper inftruments, to make fuch obfervations on various 
hills in England and Scotland, as might enable us to 
choofe the fitteft for the purpofe. Accordingly Mr. 
CHARLES MASON, wlio had been employed on feveral af- 
tronomical occalions by the Royal Society, was appointed 
to make a tour through the Highlands of Scotland in the 
fummer of the year 1773, taking notice of the principal 
hills in England which lay in his route either in his going 
or in his return. It appeared from his obfervations, that 
fcarce any hill was fo well adapted to the purpofe as our 
fanguine hopes had led us to expe6t; for either they 
w^ere not high enough, or not fufficiently detached from 
other hills, or their greateft length fell in a wrong direc- 
tion, too near the meridian, inftead of lying nearly Eaft 
and Weft, which is a circumftance requifite to make a 
hill of a given height afford the greateft effecft of attrac- 
tion. In particular, the hills on the confines of York- 
fhire and Lancafhire, mentioned in the foregoing propo- 
dal, were found not to anfwer the defcription that had 
been given of them. Fortunately, however, Perthfhire 
afforded us a remarkable hill, nearly in the centre of 
Scotland, of fufhcient height, tolerably detached from 
(Other hills, and confiderably larger from Eaft to Weft, 
than from North to South, called by the people of the 
low 
